Fix: Possible dereference of null pointers

[lttng-tools.git] / src / common / sessiond-comm / unix.c

diff --git a/src/common/sessiond-comm/unix.c b/src/common/sessiond-comm/unix.c
index fea56e8efa19a404bc1170627ef5300101a39f4a..77a6013f0244572b2c2bb30ae054959db2cdf5c4 100644 (file)
--- a/src/common/sessiond-comm/unix.c
+++ b/src/common/sessiond-comm/unix.c
@@ -17,6 +17,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <limits.h>
 #include <stdio.h>
@@ -92,6 +93,16 @@ int lttcomm_accept_unix_sock(int sock)
        return new_fd;
 }
 
+LTTNG_HIDDEN
+int lttcomm_create_anon_unix_socketpair(int *fds)
+{
+       if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
+               PERROR("socketpair");
+               return -1;
+       }
+       return 0;
+}
+
 /*
  * Creates a AF_UNIX local socket using pathname bind the socket upon creation
  * and return the fd.
@@ -125,6 +136,11 @@ int lttcomm_create_unix_sock(const char *pathname)
        return fd;
 
 error:
+       if (fd >= 0) {
+               if (close(fd) < 0) {
+                       PERROR("close create unix sock");
+               }
+       }
        return ret;
 }
 
@@ -167,7 +183,7 @@ ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
 
        do {
                len_last = iov[0].iov_len;
-               ret = recvmsg(sock, &msg, 0);
+               ret = recvmsg(sock, &msg, MSG_NOSIGNAL);
                if (ret > 0) {
                        iov[0].iov_base += ret;
                        iov[0].iov_len -= ret;
@@ -265,6 +281,9 @@ ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
        msg.msg_controllen = CMSG_LEN(sizeof_fds);
 
        cmptr = CMSG_FIRSTHDR(&msg);
+       if (!cmptr) {
+               return -1;
+       }
        cmptr->cmsg_level = SOL_SOCKET;
        cmptr->cmsg_type = SCM_RIGHTS;
        cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
@@ -392,6 +411,9 @@ ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
        msg.msg_controllen = CMSG_LEN(sizeof_cred);
 
        cmptr = CMSG_FIRSTHDR(&msg);
+       if (!cmptr) {
+               return -1;
+       }
        cmptr->cmsg_level = SOL_SOCKET;
        cmptr->cmsg_type = LTTNG_SOCK_CREDS;
        cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
@@ -430,6 +452,7 @@ ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
        struct msghdr msg;
        struct iovec iov[1];
        ssize_t ret;
+       size_t len_last;
 #ifdef __linux__
        struct cmsghdr *cmptr;
        size_t sizeof_cred = sizeof(lttng_sock_cred);
@@ -456,12 +479,21 @@ ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
 #endif /* __linux__ */
 
        do {
+               len_last = iov[0].iov_len;
                ret = recvmsg(sock, &msg, 0);
-       } while (ret < 0 && errno == EINTR);
+               if (ret > 0) {
+                       iov[0].iov_base += ret;
+                       iov[0].iov_len -= ret;
+                       assert(ret <= len_last);
+               }
+       } while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
        if (ret < 0) {
                PERROR("recvmsg fds");
                goto end;
+       } else if (ret > 0) {
+               ret = len;
        }
+       /* Else ret = 0 meaning an orderly shutdown. */
 
 #ifdef __linux__
        if (msg.msg_flags & MSG_CTRUNC) {
@@ -534,45 +566,3 @@ int lttcomm_setsockopt_creds_unix_sock(int sock)
 #else
 #error "Please implement credential support for your OS."
 #endif /* __linux__ */
-
-/*
- * Set socket reciving timeout.
- */
-LTTNG_HIDDEN
-int lttcomm_setsockopt_rcv_timeout(int sock, unsigned int sec)
-{
-       int ret;
-       struct timeval tv;
-
-       tv.tv_sec = sec;
-       tv.tv_usec = 0;
-
-       ret = setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
-       if (ret < 0) {
-               PERROR("setsockopt SO_RCVTIMEO");
-               ret = -errno;
-       }
-
-       return ret;
-}
-
-/*
- * Set socket sending timeout.
- */
-LTTNG_HIDDEN
-int lttcomm_setsockopt_snd_timeout(int sock, unsigned int sec)
-{
-       int ret;
-       struct timeval tv;
-
-       tv.tv_sec = sec;
-       tv.tv_usec = 0;
-
-       ret = setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
-       if (ret < 0) {
-               PERROR("setsockopt SO_SNDTIMEO");
-               ret = -errno;
-       }
-
-       return ret;
-}